Progressive Care Nursing Certification (PCCN) Practice Exam

What indicates an active pleural air leak in a patient with a chest tube system?

1. Bubbling in the water-seal chamber

2. Bubbling in the suction control chamber

3. Fluctuation of water level in the water-seal chamber

4. No fluctuation of water level in the water-seal chamber

The correct answer is: Bubbling in the water-seal chamber

Bubbling in the water-seal chamber of a chest tube system is a significant clinical indicator of an active pleural air leak. When air from the pleural space enters the pleural cavity, it is forced through the chest tube and into the water-seal chamber, causing visible bubbles to rise in the water. This bubbling reflects the presence of air escaping from the pleural cavity, signifying that the lung is not fully re-expanded and that there might be an ongoing leak from the pleura to the external environment. In contrast, bubbling in the suction control chamber is related to the application of suction and does not indicate a pleural air leak. Fluctuation of the water level in the water-seal chamber—known as tidaling—occurs as the patient breathes and is considered a normal finding when a lung is re-expanding. No fluctuation in the water-seal chamber suggests that there may be a blockage in the system or that the lung has re-expanded adequately, thus eliminating any active air leak. Therefore, bubbling in the water-seal chamber distinctly indicates an ongoing air leak situation.